NEW YORK (Reuters) - A U.S. federal judge has denied a request by Orbitz Worldwide Inc (>> Orbitz Worldwide, Inc.), Sabre Holdings Corp and Travelport Ltd to dismiss a lawsuit filed by American Airlines Inc that accuses the companies of antitrust violations.

The decision by U.S. District Judge Terry Means in Fort Worth, Texas, which had been under seal, was made public on Tuesday following a request by the parties to unseal the order.

American Airlines, whose parent company is AMR Corp (>> AMR Corporation), accused the defendants of monopolizing how fares and flights are distributed to travel agents.

Orbitz is an online travel agency, Travelport provides transaction processing and Sabre runs a distribution system that delivers fare and flight information to travel agents.

"We continue to dispute these allegations and will defend ourselves vigorously, with the expectation that Orbitz will prevail," Orbitz Worldwide spokesman Chris Chiames said.

Judge Means had previously dismissed some claims by American Airlines, but he allowed the company to submit a second amended complaint. In his most recent decision, Means found that American had adequately alleged that the defendants engaged in a conspiracy to preserve their market power.

Nancy St. Pierre, a spokeswoman for Sabre, said the company would continue to "vigorously defend ourselves against these baseless and meritless claims."

American Airlines and Travelport officials did not respond immediately to a request for comment.

The case is American Airlines Inc. V. Travelport Ltd et al, U.S. District Court, Northern District of Texas, No 11-0244.

(Reporting by Andrew Longstreth; additional reporting by Sakthi Prasad; Editing by Paul Tait and Matt Driskill)

Stocks treated in this article : AMR Corporation, Orbitz Worldwide, Inc.